1. Field of the Invention
The present invention relates to advertising displays and more particularly to a drive control and interface apparatus for sequentially displaying multiple images in an advertising display.
2. Description of the Prior Art
With the advent of modern display advertising, limitations on advertising budgets and limited locations for display to high densities of consumers, a great demand has arisen for display advertising which utilizes attention grabbing animated displays and multiple display advertisements at individual popular display locations to thereby improve communication of the advertiser's message and enable a number of advertisers to benefit from a single location. Numerous different methods and devices have been proposed for preparing and displaying such advertisements. Many such devices involve relatively unwieldy mechanical elements driven by complex drive mechanisms which require a certain degree of mechanical precision. Thus, in addition to the expense of original manufacture, the user is often faced with expensive maintenance.
In addition, operation of these drive mechanisms tends to produce an undesirable amount of noise. Typically, these devices are used in public retail outlets or other public locations where the noise level of the drive mechanism frequently predominates over the background music being played at such locations. This noise detracts from the overall ambiance sought by the retailers using the advertising displays as a promotional tool.
It is desirable to have a system that displays multiple images wherein the exchange from one image to another is nearly instantaneous thereby enabling the sequential display of different images to produce the impression of animation. Such a sequential display would draw and hold a viewer's attention on what would appear to be an animated advertisement. However, quiet operation during image sequencing is desirable to minimize distraction from the overall environment where the system is located.
Display devices including templates with patterns of apertures which define numbers, letters or figures when they are illuminated by back lighting have been described. See, e.g., Hildburgh, U.S. Pat. No. 1,172,455, and Kass, U.S. Pat. No. 2,982,038. There have also been described display devices including transparency sheets which have images thereon and which are illuminated by back lighting and an overlay mask which blocks the back lighting from illuminating certain areas of the transparency sheets. See, e.g., Elvestrom, U.S. Pat. No. 3,000,125, Fukui, U.S. Pat. No. 3,683,525, and Hasala, U.S. Pat. No. 3,742,631.
In addition, devices have been proposed which include a translucent image screen made up of a mosaic of discrete images formed by relatively small interlaced translucent pixels or window segments which are arranged in uniform groups. The pixels corresponding to a discrete image occupy the same relative position in each group and bear corresponding magnitudes of translucency. The image screen may then be covered with an opaque screen having a uniform pattern of transparent display apertures. The opaque screen blocks back lighting from shining through the image screen except through the display apertures. The uniformly patterned display apertures are then aligned with pixels which correspond to a discrete image and the discrete image is thereby displayed due to the back lighting shining through the image screen and display apertures. The opaque screen may then be selectively shifted on the image screen such that the display apertures align with the pixels of a different discrete image. Thus, each discrete image may be sequentially displayed.
A device of this general description is shown in U.S. Pat. No. 4,897,802 to Atkinson et al., assigned to the assignee of the present application. The device, as described in that patent, exhibits excellent operational characteristics. However, it is desirable to have a more economical and reliable drive and interface system which enables convenient and accurate sequential display of the images that enables relatively noise free operation.
Drive systems using stepper motors controlled by an electronic circuit have been used on devices that exhibit quiet drive characteristics. See Pritchard, U.S. Pat. No. 4,087,732 and Cotu, U.S. Pat. No. 5,225,756. Such devices have been disclosed for use on laser printers and facsimile machines. See also Nakamura, U.S. Pat. No. 5,231,343 using a quiet drive apparatus for use with an automotive odometer. While these devices are fit for their intended purpose, they do not disclose a low cost quiet drive apparatus that enables the timed display of sequential images for selectively displaying multiple images to produce an animated effect or for the display of several images at one location.